Idle stop interlock



June 20, 1961 Filed Aug. 13, 1959 H. s. WILLIAMS IDLE STOP INTERLOCK 2Sheets-Sheet 1 INVENTOR. 441010 J; lfl/ll/M/J Y 9 June 20, 1961 H. s.WILLIAMS IDLE STOP INTERLOCK 2 Sheets-Sheet 2 Filed Aug. 13, 1959INVENTOR. 6mm! a? 17/11/4411 BY men/116 United States Patent IDLE STOPINTERLOCK Harold S. Williams, Galesburg, Ill., assignor to OutboardMarine Corporation, Waukegan, 111., a corporation of Delaware Filed Aug.13, 1959, Ser. No. 833,506

6 Claims. (Cl. 74-472) This invention relates to improvements in adevice for preventing the undesired stopping of an outboard boat motorwhen it is being operated at slow speed or when the gears are beingshifted from forward to reverse or vice versa.

When a boat driven by an outboard motor is approaching a dock or isbeing used for purposes requiring relatively slow speed for aconsiderable length of time or when the boat is being maneuvered so thatthe gears are frequently shifted to change the direction of motion ofthe boat, the engine should continue to run at low speed but manyengines will stop unless the operator has considerable skill andexperience in their operation. Upon stopping of the engine control ofthe boat is lost, which is at least annoying and can be dangerous undersome conditions of water currents or of wind.

In two-cycle internal combustion engines particularly, the speed iscontrolled in part by the timing of the spark and in part by thethrottle opening and these may be operated by a single operator controlhaving provisions for optimum coordination. A connection is thereforeprovided between the timer plate and the carburetor throttle valve formaintaining the proper relation between the two speed control factors.This connection may be constructed according to the disclosure of Patent2,906,251. The specific form of the connection is not a part of thepresent invention, and so will not be shown in full. A conventionalmagneto (not shown) is mounted on the timer plate to interact with amagnet rotated by the crankshaft of the engine, the interactionoccurring at an angular position of the crankshaft determined by theangular position of the timer plate, as is conventional. Other methodsof varying the timing may also be used. The carburetor and throttle mayalso be conventional. According to my invention means are also providedfor inter-connecting the plate controlling the spark timing with thegear shift lever to limit the movement of the timer plate when gears areengaged, so that the throttle valve cannot be completely closed so longas gears are engaged. The present device is in effect an interlockbetween the gear shift lever, the timer plate and the throttle, which isso adjusted that the throttle and timer plate cannot be shifted belowidling speed position while the gears are engaged for either forward orreverse drive, thus freeing the operator from the necessity of lookingat the throttle to see the mark for idling position. This isparticularly important in an emergency when speed must be reducedwithout stopping the engine. The interlock does not interfere withstopping the motor when the gear shift lever is in neutral position sothat no gears are engaged.

In the drawings:

FIGURE 1 is a side elevational view of an outboard boat motor with partsbroken away and parts in section to show the structure involved in thepresent invention;

FIGURE 2 is a View similar to FIGURE 1 but taken at 90 to FIGURE 1;

FIGURE 3 is a perspective view of the control means and interlocksshowing their relationship;

FIGURE 4 is a perspective view of the lock lever for acting on the gearshift lever; and

FIGURE 5 is a modified form of the lock lever shown in FIGURE 4, whichallows emergency stopping of an engine equipped with such lock while thegears are engaged.

FIGURES 1 and 2 show an outboard motor generally indicated at 10, andincluding an internal combustion engine (not shown) having a flywheel 11and a timer plate 12, a gear shift lever 13 and a tiller handle 14 .(seeFIGURE 3). The gear shift lever 13 is pivoted at 15 and is connected bya linkage 16 with a shifter rod 17 extending into lower unit 21 wherethe rod is pivoted at 22 to a shifter yoke 23, the yoke being pivoted onthe lower unit at 24. As the shifter rod 17 is moved vertically, theyoke 23 acts on shift collar 25 to couple gear 26 or gear 27 topropeller shaft 28 to rotate it in the desired direction or uncouple italtogether, power being supplied to gears 26 and27 continuously by wayof a drive shaft 29 and a pinion 30 in constant mesh with gears 26 and27.

The gear shift lever 13 carries a pin 33 which is selectively engageablein notches A, B or C (see FIG- URES 3, 4 and 5) on a shifter lock lever34 pivoted at 35 to swing toward and away from the gear shift lever pin33 under the action of spring 36 which is seated on a fixed portion 37of the power head 10. A bracket 38 is mounted on the timer plate 12 tosupport a screw 39 under the action of a compression spring 40 actingbetween the bracket and the screw head, the screw being adjustable toextend into the path of movement of the lock lever 33. The spring may bereplaced by a lock nut or any well known means for holding screw 39 inits adjusted position. The notches A, B and C of lock lever 34 arerespectively engaged by the shifter lever pin 33 when the gear shiftlever 13 is in forward, neutral and reverse positions.

Referring now to FIGURE 3 a handgrip on the tiller handle 14 is attachedto an oscillating shaft 43, with a universal joint 44 connecting saidwith a shaft 45 having a bevel gear 46 thereon. The bevel gear 46 actson a bevel gear 47 to transmit motion to a rock shaft 48, the rock shaftbeing turned clockwise as the handgrip 14 is turned in a direction toaccelerate the motor. A rocker arm 49 on the upper end of the rock shaft48 is pivoted at 50 to a link 51 having its remote end pivoted at 52 toa plate 53 itself pivoted to the under side of the timer plate 12 andmovable against a stop 54. When the link 51 is moved by clockwiseoscillation of the rocker arm 49, the link 51 presses on the pivot 52 inclockwise direction and rotates the timer plate 12 to advance the timingof the spark to the internal combustion engine in a wellknown manner. Atthe same time a rod 58 mounted on the pivot 50 acts on the throttlevalve of the carburetor (not shown) to open the valve.

When the gear shift lever 13 is in neutral position with its pin 33engaging notch B of lock lever 34, neither gear 26 nor gear 27 isengaged with the propeller shaft 28 and the engine may be started, idledor stopped. Stopping of the engine is accomplished by turning the handle14 to turn the timer plate 12 in counter-clockwise direction and closethe throttle. When the gear shift lever 13 is in neutral position, thelock lever 34 is in the dotted line position shown in FIGURE 2, so thatthe timer plate 12 may carry the screw 39 past the lock lever 34 and thescrew does not interfere with the starting, idling or stopping of theengine.

However, when the gear shift lever 13 is in position to engage its pin33 in either notch A or notch C of lock lever 34 for engagement of gear26 or 27 to the propeller shaft 28, the lock lever 34 is in the solidline position shown in FIGURE 2. Movement of the timer plate 12 incounter-clockwise direction to retard the spark and to close thethrottle valve nowv brings the screw 39 against the lock lever 34 tolimit the degree to which the speed control means may be turned inclosing direction and 3 the engine continues to operate at an idlingspeed dependent on the adjustment of the screw 39. Such screw adjustmentis made only after the engine is warm so that a desired low speed ismaintained at all times during usual engine operation.

If desired, the lock lever 34 may be provided with a lateral cam surfaceindicated at 60 in FIGURE 5 by twiste ing the lock lever so thatforcible turning of the timer plate 12 will bypass the lock for stoppingthe engine under emergency conditions. Forcible turning of the timerplate causes the screw 38 to press on cam surface 60 and forces it intothe dotted line position shown in FIGURE 2. In such position, the screw38 may move past the look so that the timer plate 12 can be rotatedsufficiently to bring the throttle valve into completely closedposition.

I claim:

1. In an internal combustion engine provided with ignition means, fuelsupply means, manually operated engine speed control means forsimultaneously adjusting the fuel supply and the timing of the ignitionmeans, a plurality of gears for transmitting power from the engine to apropeller, and a manually operable control for shifting the gears, theimprovement comprising a lever adapted to be pivoted into differentpositions related to positions of the gear shift control, and means onthe engine speed control for engagement with the lever in several of itspositions of engagement with the gear shift control whereby freedom ofmovement of the speed control means in the direction for stopping theengine is limited.

2. The device of claim 1 in which said stop means is mounted formovement into and out of the path of movement of said lever forpreventing movement of the gear shift control into positions engagingthe gears in driving relation when said speed control is set below thepredetermined minimum.

3. In an outboard motor provided with an engine, gear means controlledby a gear shift lever, ignition timing control means mounted on a timerplate, the timing of the ignition being responsive .to the position ofsaid timing control means and said timer plate being movable to varysaid position, a carburetor having a throttle, and an 4 engine speedcontrol adapted to adjust the timer plate and the throttle, theimprovement comprising a device for preventing undesired stoppage of theengine when the gear shift lever is in gear engaging position, a locklever urged into position for engagement with the gear shift lever inany one of three gear shift lever positions, and an adjustable screwmounted on the timer plate for engagement with the lock lever uponmovement of the timer plate in engine-stopping direction.

4. The device of claim 3 in which a gear shift engaging cam surface isprovided on said lock lever to urge it into position for engagement bythe screw only when the gear shift lever is in position for meshing ofthe gears.

5. A device for limiting the stoppage of a fuel burning outboard motorengine geared to a propeller and having a lever for shifting the gears,said engine being provided with a timer plate mounted for limitedrotation with respect to the engine, with a linkage for rotating theplate, and with means for controlling the timing of the ignition of fuelin said engine upon rotation of the plate, said plate being furtherprovided with means to control the flow of fuel to said engines as saidplate is rotated, said device comprising, a lock lever engaged with thegear shift lever and pivoted into different positions upon movement ofthe gear shift lever, said lock lever extending adjacent the timerplate, and a stop screw adjustably mounted on the timer plate forengagement with the lock lever in two positions of the gear shift lever,engagement of the lock and the screw being adapted to limit movement ofthe timer plate and of the linkage in the direction for stopping theengine.

6. The device of claim 5 in which the lock has a cam surface engageableby the screw whereby forcible movement of the timer plate and of thelinkage forces the lock out of engagement with the gear shift leverregardless of the position of the gear shift lever.

References Cited in the file of this patent UNITED STATES PATENTS

